The purpose of the proposed study is to integrate clinical research on behavioral characteristics of children with attention-deficit hyperactivity disorder (ADHD; i.e., hyperactivity) with social psychological research on interpersonal expectancy effects. An important component of ADHD is that ADHD children experience considerable levels of social rejection by their peers. Although peer rejection has been associated with negative mental health outcomes in adulthood, until recently surprisingly little research has looked at ADHD children's interactions with peers. Thus, the primary goal of the proposed research is to examine more closely interactions between normal and ADHD children, and more specifically, to investigate the role of peers' expectations in determining the nature of the interaction. A large social psychological literature has demonstrated that, in adults, expectations can act as self-fulfilling prophecies, but few if any studies have examined expectancy effects in children. In the proposed study, sixty normal children ("expecters") will be paired for a 12 minute interaction with either an ADHD or normal partner. In half of the cases, the expecter will have been given a prior expectancy that is consistent with the actual status of the expectee, and in the other half of the cases, the expectancy will be inconsistent. This crossing of expectancy with status, called a "balanced placebo design," permits the assessment of the impact of children's reputations on their peers, above and beyond their actual behavior. Videotapes of the interactions will be coded for a number of verbal and nonverbal behaviors, and analyses will focus on identifying the social behavioral differences between ADHD children and normal children, and how expectations lead to differences in the behavior of normal peers. The proposed study would therefore make three major contributions: (a) it would extend social psychological research on expectancy effects to a child clinical population, (b) it would increase our understanding of the social behavior patterns in ADHD children, and (c) it would further examine the impact of ADHD children's reputation and behavior on normal peers' perceptions and reactions. Thus this research could ultimately aid in the development of improved social skills interventions for ADHD children.